Sets: M, N,... mathend000#
Special sets: $\mathbb {R}$,$\mathbb {Z}$,$\mathbb {C}$,$\mathbb {N}$,... mathend000#
Set operations: $\cup$ mathend000#, $\cap$ mathend000#, $\bar{{~}}$ mathend000# , $\setminus$ mathend000#, x mathend000# (Cartesian product)
Set power: Mⁿ = $\underbrace{{M\times M\times\ldots\times M}}_{{n\text{~times}}}^{}\,$ mathend000#
Function: f : M $\rightarrow$ N,    f (x) = y    (x $\in$ M, y $\in$ N) mathend000#